Sister joining on student visa

Hi,

My wife is on a student visa in Belgium.

Can she invite her sister to visit her?

Will there be any required documents?

Hi,

No, she can't

so even fir a visit visa she can't?

Your sister can ask for tourist visa, that's not the problem. But she can't use your wife as reference...

A student is not supposed to make a commitment of care for someone wishing to spend a few days in Belgium.

The only person who could do it is you. If you have a work permit and a Belgian resident visa.